$ {-2\cdot \left[ \begin{array}{cc} -1 & 3 \\ 4 & 2 \end{array} \right]=}$
Answer: The Strategy To multiply a matrix by a scalar, we multiply each term of the matrix by the scalar. Multiplying each term $ {\begin{aligned}-2\cdot \left[\begin{array}{rr} {-1} & {3} \\ {4} & {2} \end{array}\right]&=\left[\begin{array}{rr} -2\cdot{-1} & -2\cdot{3} \\ -2\cdot{4} & -2\cdot{2} \end{array}\right] \\\\&=\left[\begin{array}{rr} {2} & {-6} \\ {-8} & {-4} \end{array}\right]\end{aligned}}$ Summary $ {-2\cdot \left[ \begin{array}{cc} -1 & 3 \\ 4 & 2 \end{array} \right]=\left[ \begin{array}{cc} 2 & -6 \\ -8 & -4 \end{array} \right]}$